Shape Memory Effects in TiNi-Bbased Alloys Subjected to Electroplastic Rolling

Shape memory alloys (SMA) are well known due to their functional properties such as shape memory effect, superelasticity and etc.  Last years it has been shown that the functional properties can be improved by formation of a nanocrystalline structure by severe plastic deformation (SPD). For example, it is shown that structure refinement of the TiNi alloy by SPD leads to a significant increase in strength, the maximum recovery strain and recovery stress [1,2]. One of the perspective methods for structure refinement is electroplastic rolling (EPR) [3]. In [4] it was shown that functional properties of Ti_50,0Ni_50,0 alloy subjected to EPR revealed better functional properties in comparison with the undeformed alloy. It is known that the TiNi-based alloys with different composition of Ni concentration demonstrate the different physical and mechanical properties. Hence, one may assume that EPR should influence in different manner to the functional properties in the TiNi-based alloys with different Ni concentration.

The goal of this work is the study of functional properties (recovery strain and superelasticity) of Ti_50.0Ni_50.0 and Ti_49,2Ni_50.8 alloys subjected to EPR.